KR100570882B1 - Fault finding method of capacitors with air back fire energy - Google Patents

Abstract

The present invention relates to a method for diagnosing a failure of an airbag ignition energy capacitor included in a general airbag ignition device and diagnosing contact disconnection of a capacitor charging airbag ignition energy to generate an alarm.

According to the present invention, the contact disconnection phenomenon between the airbag ignition energy capacitor and other electrical components (eg, charging resistor, ignition circuit) included in the airbag ignition device can be easily diagnosed, and therefore, the capacitor is It is possible to solve the conventional problem that the airbag does not operate normally even when the airbag controller outputs an airbag ignition signal to drive the ignition circuit because it is not sufficiently charged to generate a normal ignition current.

Airbag, airbag ignition energy capacitor, airbag system

Description

FAULT FINDING METHOD OF CAPACITORS WITH AIR BACK FIRE ENERGY}             

1 is a block diagram showing a general airbag ignition device.

2 is a flow chart illustrating a method for diagnosing a failure of an airbag ignition energy capacitor according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: boost circuit

20: Step Down Converter

30: ignition circuit

31: Airbag

40: controller

R: charge resistance

C: capacitor

The present invention relates to an airbag ignition device for a vehicle, and more particularly to a method for diagnosing a failure of an airbag ignition energy capacitor.

In general, an airbag ignition device installed in a vehicle is configured to protect a driver, a passenger seat occupant, etc. of the vehicle by deploying a plurality of airbags disposed in the vehicle when a vehicle crash occurs.

Referring to Figure 1, a general airbag ignition device operates as follows.

When the ignition switch of the vehicle is turned on, the boost circuit 10 boosts and outputs a battery power source (Vbatt: 12V) of the vehicle to a boost voltage of 30V.

At this time, the boost voltage is supplied to a capacitor (C) for charging electrical energy for forming an ignition current required for airbag ignition through a charging resistor (R) to charge the capacitor (C), and the capacitor (C) When the ignition circuit 30 is driven by the airbag ignition signal after fully charged, the capacitor C supplies an ignition current for deploying the airbag 31 through the ignition circuit 30.

In addition, the boost voltage is supplied to the step-down converter 20, the pressure is reduced to the 5V driving voltage of the controller 40 for outputting an airbag ignition signal for driving the ignition circuit 30 to the controller 40 Stable supply

On the other hand, with respect to the capacitor (C) for charging the airbag ignition energy of the general airbag ignition device operating as described above conventionally diagnosed the operation such as the internal short phenomenon, uncharged, etc. to determine whether the failure.

However, according to the failure diagnosis method, a failure diagnosis of the capacitor C itself is possible, but disconnection between the capacitor C and the charging resistor R or between the capacitor C and the ignition circuit 30 is performed. The phenomenon has the disadvantage of not being diagnosed.

In fact, if the capacitor C is not sufficiently charged to form a normal ignition current due to the contact disconnection phenomenon of the capacitor C, the controller 40 outputs an airbag ignition signal to generate the ignition circuit ( Even if 30 is driven, the airbag 31 does not operate normally.

The present invention is to solve the above-described conventional problems, an object of the present invention is to diagnose the fault of the contact of the capacitor included in the general airbag ignition device to charge the airbag ignition energy to diagnose the failure of the airbag ignition energy capacitor to generate an alarm To provide a method.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

The airbag ignition energy capacitor failure diagnosis method according to the present invention is performed by the controller 40 of the general airbag ignition device as shown in FIG.

When the airbag ignition device is powered on as the vehicle's ignition switch is initially turned on (S10), the controller 40 drives a cold reset determination program mounted therein so that the current state of the vehicle's ignition switch is As it is turned off and then on again, it is determined whether the power of the airbag ignition device is turned on in the cold reset state (S12).

If the current airbag ignition device power-on state is determined to be a cold reset state, the controller 40 causes the battery output power of the vehicle to return to the boost circuit 10 after a specific time (eg, 200 to 300 ms) has elapsed. It is determined whether a power-down phenomenon that is normally cut off while being supplied normally occurs (S14).

At this time, when a power down phenomenon occurs, the charging characteristic of the ignition energy charging capacitor C of the airbag ignition device may indicate an abnormal state, and thus, a misdiagnosis may occur, so that the controller 40 terminates the failure diagnosis.

On the contrary, if the power down phenomenon has not occurred, the controller 40 successively determines whether the boost voltage of the boost circuit 10 of the airbag ignition device is at a normal level (for example, 30V) (S16).

In this case, when the boost voltage is determined to be an abnormal level (for example, less than 30V), since the charging characteristic of the ignition energy charging capacitor C of the airbag ignition device may indicate an abnormal state, the controller 40 may generate a misdiagnosis. Terminate the fault diagnosis.

However, when the boost voltage is determined to be at a normal level, the controller 40 may be configured to have an upper end of the ignition energy charging capacitor C of the airbag ignition device, that is, between the capacitor C and the charging resistor R or the capacitor ( The voltage at the contact point A between C) and the ignition circuit 30 is measured (S18).

Subsequently, the controller 40 compares the magnitude of the boost voltage with the upper measured voltage of the capacitor C to determine whether the upper measured voltage of the capacitor C is smaller than a preset reference value. Determine (S20).

If the upper measured voltage of the capacitor C is determined to be smaller than or equal to a preset reference value compared to the boost voltage, the controller 40 determines that the contact state of the capacitor C is faulty every time. After increasing the number of failures in the memory by one (S22), it is determined whether the number of failures currently recorded in the internal memory is a specific number of failures (for example, five times) set in advance to notify the fixed alarm (S24).

At this time, if the number of failures currently recorded in the internal memory is less than a predetermined number of failures (for example, five times) set in advance to notify the fixed alarm, the controller 40 may turn on the airbag ignition device power as the ignition switch of the vehicle is turned on. Return to the on determination step S10.

On the other hand, if the number of failures currently recorded in the internal memory is a predetermined number of failures (for example, five times) set in advance to notify the fixed alarm, the controller 40 detects a failure in the contact state of the airbag ignition energy capacitor C. Generate an alarm for notifying (S26).

On the other hand, if the upper measured voltage of the capacitor (C) is not determined to be smaller than the preset reference value compared to the boost voltage (S20), each time the controller 40 is determined that the contact state of the capacitor (C) is normal After the determination is made, the failure count value recorded in the internal memory is reset to 0, and the flow returns to the airbag ignition device power on determination step S10 in response to the ignition switch of the vehicle being turned on (S28).

As described above, the airbag ignition energy capacitor failure diagnosis method according to the present invention is included in the general airbag ignition device, and diagnoses the disconnection of the capacitor charging the airbag ignition energy, thereby generating an alarm, which is included in the capacitor and the airbag ignition device. Since disconnection of contacts between other electrical components (e.g., charging resistors, ignition circuits) can be easily diagnosed, airbag controllers are not sufficiently charged to allow the capacitor to form a normal ignition current due to such contact disconnection. Even if the airbag ignition signal is output to drive the ignition circuit, the conventional problem that the airbag does not operate normally can be solved.

What has been described above is only one embodiment for implementing the airbag ignition energy capacitor failure diagnosis method according to the present invention, the present invention is not limited to the above-described embodiment, the present invention as claimed in the following claims Without departing from the gist of the present invention, one of ordinary skill in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (1)

When the airbag ignition device is powered on as the ignition switch of the vehicle is turned on (S10), determining whether the power of the airbag ignition device is a cold reset state (S12); If it is a cold reset state, determining whether a power-down phenomenon of a battery output power of a vehicle occurs after a specific time elapses (S14); Determining that the boost voltage of the boost circuit 10 of the airbag ignition device is at a normal level if a power down phenomenon has not occurred (S16); If the boost voltage is determined to be at a normal level, measuring the voltage at the top contact A of the ignition energy charging capacitor C of the airbag ignition device (S18); Comparing the upper measured voltage of the capacitor C with the magnitude of the boost voltage to determine whether the upper measured voltage of the capacitor C is smaller than a preset reference value or less than a boost voltage (S20); When the upper measured voltage of the capacitor C is determined to be smaller than the preset reference value compared to the boost voltage, it is determined that the contact state of the capacitor C is a fault every time and the number of times of failure is increased by 1 in the internal memory. After the operation (S22), as a result of determining whether the number of failures currently recorded in the internal memory is a predetermined number of failures set in advance to notify the fixed alarm, if the number of failures is smaller than the specific number of failures, the airbag ignition device according to the on-ignition switch of the vehicle Returning to the power on determination step S10 (S24); (S26) generating an alarm for notifying the driver of a failure of the contact state of the airbag ignition energy capacitor C when the number of failures currently recorded in the internal memory is a predetermined number of failures set in advance to notify the fixed alarm; And If the measured voltage of the upper end of the capacitor (C) is not determined to be smaller than the preset reference value or less than the boost voltage in step S20, it is determined that the contact state of the capacitor (C) is normal every time the number of failures recorded in the internal memory After resetting the value to 0, returning to the airbag ignition device power on determination step (S10) as the ignition switch of the vehicle is turned on (S28). Airbag ignition energy capacitor failure diagnosis method, characterized in that consisting of.

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